It depends on the activities. For vocabulary learning, a smartphone is very convenient. If you are on the go, it's a suitable time to study vocabulary. However, for exercises that involve reading longer documents, a smartphone may not be as practical, and it's preferable to use a computer or tablet. In general, navigating the website with a tablet or computer is more comfortable.

Vocabulary learning is completely free. As for the exercises, when you create an account, you are given 50 credits which allow you to do 50 exercises. After that, you have two options. Option one: if you only want to do activities for about 10 to 15 minutes per month, you can wait for your account to recharge monthly. Option two: if you need to do more exercises, for example, at least 15 to 20 minutes per week, you can choose a premium access.

Revisions are extremely important. They guarantee long-term knowledge retention.

On the revision page, pay attention to the icons (dogs) and notice that some icons are in color while others are in black and white.

Color icons represent exercises that you voluntarily keep in your list. You have the right to remove them at any time. You can also choose the time frame in which they will reappear in your list.

The black and white icons, on the other hand, represent exercises that you must successfully complete before being able to remove them from your list.

Yes, it's possible, but be careful not to overload yourself with work. If you were successful on the first try, it's not impossible that you won't need to do it again.

However, if you wish to systematically add successfully completed exercises to your revision list, there is an option to do so on this page in the learning section.